The subject invention relates to a drive assembly for independently driving dual-wheel assemblies of a vehicle.
In general, dual-wheel assemblies are utilized to increase the load capacity of a vehicle. Typically, the dual-wheel assemblies are disposed at each side of the vehicle and include inner and outer wheels with tires secured together to rotate in unison during a vehicle turn. Commonly, dual-wheel assemblies are necessary in container-loading environments, such as ship yards where cargo containers are being loaded and unloaded, and the resulting tire loads would be too large for a single tire to withstand. In such environments, vehicles are often required to continuously undergo tight turns due to the relatively confined quarters and the general congestion of such environments. The tires of the dual-wheel assemblies experience uneven and excessive wear caused by scrubbing or dragging of the tires upon the repeated turning of the vehicle. Each wheel of the dual-wheel assemblies must travel different linear distances to complete a turn. Since the inner and outer wheels are secured together, the tires scrub or drag thereby causing excessive wear.
Prior art vehicles have incorporated a primary differential between a pair of dual-wheel assemblies. A secondary conventional differential has also been arranged between the wheels of each dual-wheel assembly. Such conventional assemblies are limited in that the assemblies cannot independently drive the wheels of the dual-wheel assemblies. These assemblies do not permit one dual-wheel assembly at one side of the vehicle to be driven with driving forces which are different than those applied to the dual-wheel assembly at the other side of the vehicle, which limits maneuverability. Therefore, what is needed is a drive assembly that reduces scrub and increases maneuverability of the vehicle.